If you don't mention the negative aspects of a thing, then you're just not being "honest" or telling the "whole" story.
When you mention positive qualities without acknowledging faults, you are considered "Pollyannish" or to be wearing rose-colored classed. "Overly idealistic" or "romanticizing" or "being sentimental" or "covering up" are other terms that come to mind.
However, the opposite -- focusing on negatives without mentioning positives -- is often not considered "dishonest."
Sure, if you mention only negatives, others might consider you negative or cynical -- but usually only if you overdo it or express negativity toward ideas or things the other person likes.
Isn't it interesting that honesty and completeness depend on revealing the negatives?
Yet focusing on positive aspects doesn't mean that you don't see the faults. It doesn't even mean you are denying or trying to cover up faults.
For example, if someone pens an article on how Judaism (NOT ignorant or snobby Jews, but authentic Judaism) views baalei teshuvah or gerim, not much time goes by before someone feels compelled to write in (often hotly and bitterly) about their negative experiences as a baal teshuvah or a ger (despite the fact that wasn't the topic of the original article) or misquoting/misunderstanding Sagely statements taken out of context. This is often accompanied by accusations of "whitewashing things" and not portraying things as they really are, and so on.
At the same time, baalei teshuvah or gerim with mostly positive experiences will be dismissed by nay-sayers as being blind, brainwashed, or dishonest.
Why do negative aspects trump positive aspects?
Why are negative aspects the determining factor of truth?
It's Not a Black-and-White Issue
I read an article about the baby of a white Jewish mother and a black non-Jewish father who was adopted by a frum family.
The child was welcomed into the community and according to him and his family, never experienced racism.
Of course, an angry letter appeared in response, declaring that racism was a problem in the frum community and insinuating that something dishonest and disingenuous was going on with the way the writer presented the story.
Unfortunately and shamefully, there is racism against frum black Jews by some frum-looking Jews.
However, the article wasn't about racism in the frum community. It wasn't about racism at all.
The article was about this particular young man in this particular community, with a focus on adoption and loving an adopted child as much as your biological children, plus the experience of a biracial family.
Yet because the child had never experienced racism in his community, this angered someone because it seemed "dishonest."
(Also, in her excellent book, My Sister the Jew, Ahuvah Gray writes that while she knows some black Jews experience racism, she personally never had -- at least at the time of that writing).
So it is not a given that a black Jew will experience discrimination in his or her community, and it is neither denial nor dishonesty to say this.
In contrast, I've read articles by frum Jews condemning racism in the frum community (and rightly so), accompanied by painful stories...WITHOUT even mentioning the non-racists. Meaning, they don't mention the positive experiences or the good people at all. (Or they devote only one sentence to the good people as an aside.)
Yet regarding the lack of positive mentions, who writes in to say: "Hey, you're covering things up! You're not telling the whole story! You're not being honest!"?
To be fair, articles of condemnation are written by caring Jews who are passionate for world that is more just and compassionate, and this is their way of trying to facilitate that better world. Also, they sometimes include statements of Chazal against racist behavior to show that such behavior is against the Torah, so that's a plus.
But the point is that in the non-Jewish world, the proof of honesty and truth is acknowledging the bad.
In Judaism, it's exactly the opposite.
Viewing Events with Chazal-Colored Glasses
Whether you have the Or Hachaim explaining Hagar's poor behavior toward Sara Imeinu more as an innocent misinterpretation of Jewish Law (rather than just plain bad middot) or the Kli Yakar describing King Achashverosh's appallingly blasphemous and brazen behavior as "karov l'shogeg" ("close to being an accidental sinner") even as the Kli Yakar asserts that Achashverosh was indeed a rasha (a wicked intentional sinner), our Sages never stop seeing the light in the darkness.
(This doesn't even begin to cover their portrayal of our Torah greats in Tanach, even as they point out -- only l'toelet, purely as a teaching moment for our benefit -- the few things they did wrong, albeit with the best of intentions.)
I found this particularly fascinating because in "real" life, the greatest minds throughout history tend to be cynical, negative, and even misanthropic and suicidal (and many were immoral to boot).
So I was transfixed by these Sages who possessed even greater minds than Einstein and still viewed people with such an ayin tovah, a good eye.
Even when issuing a stern rebuke, the Sage usually ends with something like, "this sin is done out of ignorance, may Hashem help us and atone for our sins" -- i.e., judging them favorably and then wishing them well. Oh, and OUR sins? Nice of the tzaddik to include himself among us sinners!
How's that for humble?
Scaling the Cliff
In reality, refusing to acknowledge the positives is (usually) the real dishonesty and refusal to tell the whole story.
If it's inappropriate, I'm not saying that we should only talk about the positive and pretend that things are wonderful and perfect when they're not.
In order to fix problems, we need to see them.
In order to heal an illness, we need to look at the tumor or cells or germs.
But the hyperfocus on what's wrong is often a problem.
(This is why, for example, many doctors arrogantly state when a life will end upon the diagnosis of a serious illness. Looking at the illness to diagnose is fine, but hyperfocusing on everything that's wrong to the point that the doctor condemns the patient to a shortened life borders on evil. And many doctors do this with pregnancy too, which ends the life of the unborn baby.)
Furthermore, harping on what's wrong is usually not the way to fix things.
It's sort of like being stuck in the cleft of a mountain and emphasizing the impossible height to scale and the slickness of the walls while ignoring the rock-climbing equipment in your backpack.
How are you supposed to climb out if you only focus on the impossible height and the sheerness of the cleft?
Yes, you need to acknowledge the negatives so that you can set up your equipment and prepare yourself accordingly.
But that's it. Just what you need to know to figure things out.
Dwelling on the negatives any more than that can be suicidal.
The Kli Yakar on King Achashverosh (Feel free to scroll down a little over halfway until you get to The Mountain of Sludge and start reading from there to see the Kli Yakar's idea)